Apparatus and method for chemical mechanical planarization

Abstract

Generally, a semiconductor wafer processing system and more specifically, a semiconductor wafer planarization system for polishing a workpiece, such as a semiconductor substrate or wafer. The system generally includes a first polishing module that has a polishing head for retaining a workpiece, a staging module and a set of load cups for transferring the workpiece to and from the polishing head. A primary robot that has a workpiece gripper transfers the workpiece between the first set of load cups and the staging module. The staging module and the load cups comprise transfer locations where processed and unprocessed workpieces may be set within the reach of processing modules and transfer devices so that the dwell time associated with handling polished and unpolished workpieces is reduced. Additionally, a method for transferring wafers about the polishing system is also disclosed.

What is claimed is:  
     
       1. A semiconductor wafer planarization system for processing a workpiece comprising: 
       a base  
       a first linear polishing module coupled to the base and having one or more polishing heads for retaining a workpiece;  
       a staging module coupled to the base;  
       a first set of load cups disposed between the staging module and the first linear polishing module, the first set of load cups comprising at least one input load cup and one output load cup respectively coupled to the base at a fixed distance from the first linear polishing module for transferring the workpiece with the polishing head; and  
       a first robot having a workpiece gripper for transferring the workpiece between the first set of load cups and the staging module.  
     
     
       2. The planarization system of  claim 1  further comprising: 
       at least a second polishing module having a polishing head; and  
       at least a second set of load cups for transferring the workpiece between the polishing head wherein the workpiece is accessible to the workpiece gripper of the first robot.  
     
     
       3. The planarization system of  claim 2 , wherein the first polishing module comprises two polishing heads, the first set of load cups comprises four load cups, the second polishing module comprises two polishing heads and the second set of load cups comprises four load cups. 
     
     
       4. The planarization system of  claim 1 , wherein the staging module comprises: 
       a first staging platform; and  
       a second staging platform disposed adjacent the first staging platform.  
     
     
       5. The planarization system of  claim 4 , wherein the staging module further comprises a transfer robot for transferring workpieces between the first staging platform, the second staging platform and a factory interface having one or more storage cassette. 
     
     
       6. The planarization system of  claim 5 , wherein the transfer robot further comprises an edge gripper. 
     
     
       7. The planarization system of  claim 1  wherein the first set of load cups comprises a first load cup and a second load cup. 
     
     
       8. The planarization system of  claim 1  wherein the first polishing module comprises: 
       a polishing table;  
       a drive system movably coupled to the polishing table, the polishing head coupled to the drive system of the first polishing module; and  
       a web of polishing media disposed upon the polishing table.  
     
     
       9. The planarization system of  claim 8 , wherein the drive system comprises: 
       a first linear motion device movably coupled to the polishing table; and  
       a second linear motion device movably coupled to the first linear motion device, the polishing head coupled to the second linear motion device of the drive system.  
     
     
       10. The planarization system of  claim 1 , wherein the first robot is suspended above the load cups. 
     
     
       11. The planarization system of  claim 1  further comprising: 
       a rotational buffing module; and  
       a buffing module robot wherein the buffing module robot is positioned to transfer the workpiece between the rotational buffing module and at least one of the load cups.  
     
     
       12. The planarization system of  claim 10  further comprising: 
       a base supporting the load cups and buffing module robot, wherein the first robot is suspended above the buffing module robot.  
     
     
       13. The planarization system of  claim 11  further comprising: 
       a second polishing module having a polishing head;  
       a second set of load cups comprising a first load cup and a second load cup, the first and second load cups for transferring the workpiece between the polishing head of the second polishing module; wherein the buffing module robot transfers the workpiece between one load cup of the first set of load cups, the first load cup of the second set of load cups and the staging module.  
     
     
       14. A semiconductor wafer planarization system for processing a workpiece comprising: 
       one or more linear polishing modules having at least one polishing head for retaining the workpiece;  
       at least one load cup for transferring the workpiece to and from the polishing head;  
       a rotational buffing module;  
       a buffing module robot positioned to transfer the workpiece between the buffing module and the load cup;  
       a staging module; and  
       a first robot having a workpiece gripper positioned to transfer the workpiece between the load cup and the staging module.  
     
     
       15. The planarization system of  claim 14 , wherein the at least one load cups further comprises: 
       at least one load cup for loading the polishing head of the one or more polishing modules; and  
       at least a second load cup for loading the polishing head of the buffing module.  
     
     
       16. The planarization system of  claim 14 , wherein the staging module comprises: 
       a first staging platform;  
       a second staging platform disposed adjacent the first staging platform; and  
       a transfer robot for transferring the workpieces between the first staging platform, the second staging platform and a factory interface having one or more storage cassette.  
     
     
       17. The planarization system of  claim 14 , wherein the one or more polishing module comprises: 
       a first polishing module; and  
       a second polishing module, wherein the first polishing module and the second polishing module each further comprise two polishing heads.  
     
     
       18. The planarization system of  claim 17 , wherein the at least one load cup further comprises: 
       a set of four load cups disposed adjacent the first polishing module for transferring workpieces between the polishing heads of the first polishing module; and  
       a second set of four load cups disposed adjacent the second polishing module for transferring workpieces between the polishing heads of the second polishing module.  
     
     
       19. The planarization system of  claim 14  further comprising: 
       an input module from which the workpiece may be retrieved by the first robot;  
       a cleaning module disposed adjacent the input module;  
       one or more workpiece storage cassettes; and  
       an interface robot for transferring workpieces between the cleaner and the cassettes, and the cassettes and the input module.  
     
     
       20. The planarization system of  claim 19 , wherein the first robot first robot is suspended above a base. 
     
     
       21. The planarization system of  claim 14 , wherein the buffing module further comprises a rotating buffing pad. 
     
     
       22. A semiconductor wafer planarization system for processing a workpiece comprising: 
       a base;  
       a first linear polishing module coupled to the base and having one or more polishing heads for retaining a workpiece;  
       a staging module coupled to the base;  
       a first set of load cups fixed to the base adjacent the first linear polishing module for transferring the workpiece between the polishing head;  
       a first robot having a workpiece gripper for transferring the workpiece between the first set of load cups and the staging module;  
       a rotational buffing module; and  
       a second robot having a workpiece gripper disposed below the first robot, the second robot for transferring the workpiece between the first set of load cups and the buffing module.  
     
     
       23. The planarization system of  claim 22 , wherein the first and second robots are disposed concentrically. 
     
     
       24. The planarization system of  claim 23 , wherein the at least one load cups further comprises: 
       at least one load cup for interfacing with the polishing head and the first robot; and  
       at least a second load cup for interfacing with the polishing head and the second robot.  
     
     
       25. The planarization system of  claim 23 , wherein the staging module comprises: 
       a first staging platform;  
       a second staging platform disposed adjacent the first staging platform; and  
       a transfer robot for transferring the workpieces between the first staging platform, the second staging platform and a factory interface having one or more storage cassette.  
     
     
       26. The planarization system of  claim 23 , wherein the one or more polishing module comprises: 
       a first polishing module; and  
       a second polishing module, wherein the first polishing module and the second polishing module each further comprise two polishing heads.  
     
     
       27. The planarization system of  claim 23  further comprising: 
       an input module from which the workpiece may be retrieved by the first robot;  
       a cleaning module disposed adjacent the input module;  
       one or more workpiece storage cassettes; and  
       an interface robot for transferring workpieces between the cleaner and the cassettes, and the cassettes and the input module.